Printing composition



Patented Mar. 27, 1945 PRINTING comrosrrlon Jacques Duport, Basel,Switzerland, assignor to Durand & Huguenin S. A., Basel, Switzerland,

a firm 1 No Drawing. Application April 21, 1942, Serial No. 439,916. InGermany August 31, 1939 11 Claims.

This application is a continuation-in-part of my U. S. patentapplication Ser. No. 363,235 filed on October 28, 1940, and issued onNov. 24, 1942 as Patent, No. $302,753.

This invention relates to a process for printing textile fibres withester salts of leuco vat dyestuffs andto dyestuif compositions,especially it relates to printing compositions, especiallyadapted forthe application of diflicultly soluble to insoluble ester salts,especially to diflicultly soluble to insoluble alkali ester salts.ofleuco vat dyestufis.

The ester salts of leuco vatdyestufis present in the printingcomposition may base on dyeby means of known printing methods anddeveloping the insoluble vat dyestuff by acid oxidation. This oxidizingprocess can be performed in a simple manner in a bath, containing acidand an oxidizing agent, reacting in an acid me- I dium. For a number ofpurposes it ispreferable to add the oxidizing agent to the printingpaste.

In this case oxidation is effected by simply treating the printedtextile materials in an acid bath. In practice, sodium nitrite andsodium chromate ha v 2 proved to be suitable oxidizing agents. In orderto prevent the printing colors from getting acid and to preventtherefore a premature oxidation of the ester salts, some sodiumcarbonate is generally added, In many cases, it is advantageous tosubject the printed material, before the acid treatment, to a steamingoperation. In certain cases, it is undesired to treat the printedmaterial in an. acid bath. In such cases the oxidation can be effectedby steaming in neutral steam, provided that the printing paste containsbesides the oxidizing agent a. substance yielding acid when steaming.

ester salt of leuco vat dyestuffs besides other dyestuffs and ondyestuii intermediate products.

Ester salts deriving from the various series of vat dyestuffs(indigoids, thioindigoids and all vat dyestuffs, containing theanthraquinone nucleus system) are of particular value, whereby the estersalts also may base on the various reduction products from one and thesame dyestuii. The invention in particular includes the application ofsulfuric acid esters derived from enolic compounds yielding by acidoxidation the corresponding vat dyestufi. Preparations of specialinterest and value are obtained, when using a1 kali salts of acidsulfuric acid esters of leuco vat dyestuffs, being easily obtainableaccording to known methods in stable powder form.

By a treatment with oxidizing agents and acid the water-soluble estersalts of leuco vat dyestufl's are converted into the correspondingwaterinsoluble vat dyestufls. In particular, by treatstuffs, developableby a steaming process. For the steam developing method sodium chlorateor ammonium chlorate have been found to be suitable oxidizing agents.Substances yielding acid during steaming are for instance ammoniumsalts, such as ammonium sulfate, ammonium in: salts of acid sulfuricacid esters of leuco vat I dyestufls with oxidizing agents in acidmedium, the corresponding vat dyestull's are recovered.

The printing of textile materials with salts of acid sulfuric acidesters of leuco vat dyestufls, known in the trade as Indigosols, Al-

gosols, Soledons and so on is'a known art.

"It'gen'erally comprises dissolving the ester salt in water and athickening agent, bringing the printing paste thus obtained on to thefabric oxalate and particularly ammonium thiocyanate. In 'order to.accelerate the oxidation, as a rule there is added a catalyst, such asfor instance this printing)- e. developing in neutral steam,

there exist in practice other methods, whereby the ester salts areoxidized by a drying or hanging operation, and aluminium chlorate forinstance maybe used as oxidizing agent.

In order to obtain with ester salts even prints with good penetrationinto thev fibre materials, showing a possibly high dyeing power andbrilliancy, it is necessary, that in the prepared printing colors theleucoesterysalts are present in form of a suitable dispersion. Quitegenerally first the'leuco ester salt must be dissolved in .the printingpaste. In order to obtain deep shades, a quantity of ester salt,corresponding to 2-3 parts of vat dyestuif of 100% strength period partsof printing color, must be dissolved.

main dissolved, when cooling the solution again.

Many other leuco ester salts, amongst them some of the most valuableones of beautiful shades and excellent fastness of the prints, do notshow this relatively good solubility. Some of them dissolve in thewarmth, but partly precipitate again on cooling, also in the presence ofa solvent. Still other ester salts dissolve also in the warmth only to asmall extent. When cooling the printing colors, the dissolved portionprecipitates again partly or completely. Another difficulty may alsoarise with cold printing colors, containing th ester salt insolution,when adding to such a color the oxidizing agent i. e. the acid yieldingsubstance, required for the development. In some cases suddenly, inothers on standing, the ester salt precipitates, whereby often largecrystals of the leucoester salt are formed. This is explainable by thefact, that leuco ester salts are salts of a strong acid and a strongbase, being highly dissociated in aqueous solution. Hence they aresensitive against other electrolytes and can, therefore, be salted out.In most of the cases a printing color containing the ester salt in aprecipitated state becomes useless for printing purposes, because such acolor blocks the engraving of the printing roller or because it containsthe ester salt in form of differently sized particles or in form oflarge crystals, thus preventing the production of even prints.

Prior publications disclose, that in view of the above citeddifliculties, attempts have already beenmade for improving thesolubility of ester salts of leuco vat dyestuffs.

. It has been found, that compared with the usually employed sodiumsalts of the leuco esters,

the lithium salts (see British Patent 401,137), the

alkylolamine salts (see U. S. Patent 1,954,702) and the salts withbases, obtainable by the reaction of at least one molecular proportionof an alkylene oxide with triethanolamine (see'U. S. Patent 2,159,195)show -a better solubility. All these salts show one common disadvantagein as much as on adding the usual oxidizing agents i. e. acid yieldingsubstances (such as sodium nitrite, sodium chlorate, ammoniumthiocyanate) to the printing pastes, the more diflicultly soluble sodiumor ammonium salts are'precipitated again. a

In the U. S. Patent 1,954,702 there is further proposed to add a freealkylolamine base to printing pastes, containing leuco ester salts intheir commercial form (usually the sodium salts). The application of anexcess of such a free basev is unpractical for all methods, according towhich an oxidizing agent and an acid I yielding substance are added tothe printing color. A correct dosage of these ingredients (es-- peciallyof the acid yielding substance) for the development by steamingor-hanging, is rendered excess of the free base.

asvaavo the ester salts of'luco vat dyestuffs in anoptimal degree ofdispersion suitable for printing. It is a further object to provideprinting compositions containing the difficultly soluble to insolubleester salts of leuco vat dyestuffs in an optimal degree of dispersionsuitable for printing. It is still a further object to provide printingcompositions, containing the leuco ester salts precipitated in a mostfinely-divided form, whereby the precipitated ester s'altsare present inform of particles as nearly as possible of the same size.

It is still a further object of the invention to provide printingcompositions, containing the leuco ester salts dissolved in the printingcolor. A still further object of the invention is to provide printingcompositions, containing the ester salts of leuco vat dyestuffs, besidesa suitable oxidizing agent and optionally besides an acid yieldingsubstance in an optimal degree of dispersion suitable for printing. Astill further object is to provide prints on fabrics, distinguishedby.their evenness, their brilliancy of'the shade and'b'ya maximum of dyeingpower.

These and other objects are accomplished by incorporating into a leucoester salt composi tion a salt of an organic acid, free from c'arboxylicacid ester groups, with primary to tertiary nitrogenous organic bases,containing as solubilizing group at least one hydI'QXy alkyl group.

The following organic acids have proved suitable for the formation ofsalts with bases of the diflicult or even impossible in the presence ofthe v In the U. S, Patent 2,205,032 .there is proposed preparation ofthese monoester acids, however, is

complicated and expensive. For this reason they appear not adapted forpractical use.

It is now an object of this invention to provide improved printingcompositions. containing thalene sulfonic, alkyl naphthalene sulfonic,"sulfobenzoic acid andthelilre, g g

The primary" to tertiarynitrogenous organic bases used in form oftheirsaltswithorganic acids of the above defined species, for thepreparation of the dyestufi compositionsand containing as a watersolubilizing group atfleast one by: droxy alkyl group may containaliphatiQiaro-e matic, hydroaromatic and mixed faliphatic-aroe maticradicals. f 1 f The nitrogen may form part of' aheterocyclic ring,containing besides the nitrogen atom other hetero atoms. Every one ofthe above cited ra'di-, cals again, may be composed of different organicradicals, which maybe linked together for "in-j stance by 0, s,NH,"NHCO,NH-S0z, or other linking members. Especiallygood results are obtained with organicnitrogenous-bases, contain; ing aliphatic radicals"linked together ethereal by oxygen bridges, such as they are obtainedeasily by the reaction of alkylene oxides "with suitable basescontaining hydroxy groups. The nitrogenous organic bases-may be mOIlOE,di-fl or poly; amines. Polyvalent bases may contain side-,by sidenitrogen atoms of the'various alk ylation pr arylation stages. g I

The new dyestufi preparations may also be made up with mixtures or saltsoi various bases with organic acidsfof theabove'defined species,

various bases with various organic acids.

For the preparation of the new printing-come, positions the followingorganicnitrcgenous basea:

, able liquid diluting agent.

I of other ingredients.

containing at least one hydroxy alkyl groupvin form of their salts withorganic acids of the above disclosed type have been found suitable:

Alkylolamines, respectively mixtures of the mono-, diandtrialkylolamines, alkylolalkylenediand pdlvamines-(in general thereactionproducts of halogen hydrines or alkylene oxides on ammonia,amines, hydroxyamines and polyalkylene-polyamines, in so far as prima yto tertiary amines are formed by such a process)- polyhydroxyamines,such as glucamine, diglucamine, further aromatic alkylolamines,hydroxyalkylol compounds of the heterocyclic series, not containingquaternary nitrogen atoms, such as N-hydroxyethylpiperidine orN-hydroxyethylmorpholine. Particularly suitable are nitrogenous organicbases, containing besides hydroxy groups one or more ethereal radicals,such as for instance the hydroxyethylethers of triethanolamine, ofdiethylaminoethanol, of tetraethanolethylendiamine, of asymmetricdiethyldiethanolethylendiamine, of dihydroxyethylaniline, of N-hydroxyethylpiperidine and of N-hydroxyethylmorpholine. salts of bases,containing for each alkyl radical linked with nitrogen more than oneetherbond.

According to the present invention, the dyestuif compositions can quitegenerally be prepared by mixing an enol ester compound with an organicnitrogenous compound of the above defined type, optionally in thepresence of a suit- A simple and practical form of preparation consistsin mixing a salt of an enol ester compound with a salt of the base withan organic acid of the'above described type, in substance or in thepresence of water.

In the new dyestuif preparations the above described salts act asdispersing agents in the presence of a suitable solvent. dispersionwhich may be attained depends on the properties of the enol estercompound, especially on its solubility, on the nature and of thequantity of the applied saltand also on the presence The degree ofdispersion may vary from the molecular dispersion phase to a completeprecipitation of the enol ester compound in finely divided form.

By suitably selecting the salts of the organic nitrogenous bases andproper dosage of the amount to be added to the dyestuff preparation, thedegree of dispersion of the various enol ester compounds can be adjustedin such a way, that for one and the same ester compound and forthe'selected application i. e. developing method the highest degree ofdispersion, yielding in printing on textile material a maximum yield indyeing power, is obtained. The new preparations represent a valuableimprovement in printing with enol ester compounds.

Especially the difiicultly soluble, hitherto not or only difilcultlyapplicable alkali ester salts of certain enol ester compounds may now inform of the new preparation advantageously be used for printing.

The present invention will be further de. scribed in connection with thefollowing specific examples, in which the parts are by weight and whichare given in order to illustrate this invention. It will \be realized,however, that the present invention is not limited thereto, but thatchanges may be made in the dyestuffs and ingredients and theirproportions, manipulation steps and other conditions without departingfrom the scope of the appended claims,

The degree of Example 1 The following printing preparation is made up:40 parts of the sodium salt of the acid sulfuric acid ester ofleuco-Z:1-6z5-anthraquinone-diphenylthiazol, correspondin to 50% of vatdyestufi are'dissolved in the heat with 320 parts of water, 80 parts ofthe'formiate of the trihydroxyethylether of triethanolamine and 500parts of a neutral starch tragacanth thickening. The solution is cooleddown. To the cold solution there are added, whilst stirring, 40 parts ofa solution of sodium nitrite (30%) and parts of a solution of sodiumcarbonate (10%). The preparation thus obtained contains the ester saltprecipitated in a finely divided form.

When cotton is printed with this preparation and the print steamed for 4minutes in a Mather- I Platt apparatus and afterwards developed duringExcellent results are obtained with 8' seconds at 70 C. in an acid.bath, containing 20 com. of cone. sulfuric acid per liter, there isobtained, after the usual washing and soaping at the boil, an even anddeep canary-yellow print.

In the above example the formiate of the trihydroxyethylether oftriethanolamine may be replaced by the following salts yieldingsubstantially equivalent results: acetate, lactate, oxalate, tartrate ofthe trihydroxyethylether of triethanolamine, lactate of thetetrahydroxy-polyethylether of the tetraethanol-ehylene-diamine(obtainable from tetraethanolethylenediamine and 8 molecules ofethyleneoxide).

Example 2 The following printing preparation is made up:

40 parts of the sodium salt of the acid sulfuric acid ester of leuco-221-6:5-anthraquinone-diphenylthiazol, corresponding to of vat dyestufiare dissolved by warming with 280 parts of water, 80 parts of theacetate of the trihydroxyethylether of triethanolamineand 500 parts of aneutral starch tragacanth thickening. The solution is cooled down. Tothe cold solution there are added under stirring 40 parts of a solutionof ammonium thiocyanate (50%), 50 parts of a solution of sodium chlorate(25%) and 10 parts of a solution of ammonium vanadate (1%),

whereby the ester salt precipitates in a finely I divided form.

When cotton is printed with this preparation and the print steamed for 8minutes in aMather- Platt apparatus, there is obtained, after the usualwashing and soaping at the boil, a deep and vivid canary-yellow print.

Example 3 tion of sodium nitrite (30%) and 20% of a solution of sodiumcanbonate (10%) are added, while stirring.

When cotton is printed with this preparation and afterwards developedduring 8 seconds at 70 C. in an acid bath containing 20 com. of cone.sulfuric acid per liter,. there is obtained after the usual washing andsoaping at the boil, an even deep and vivid red-orange colored print.

In the above example the formiate of the tri- I Example 4 40 parts ofthe sodium salt of the acid sulfuric acid ester ofleuco-Zzl-naphthioindigo corresponding to 50% of vat dyestuffaredissolved by heating up with 380 parts of water, 5 parts of thelactate of the trihydroxyethylether of triethanolamine and 500 parts ofa neutral starch tragacanth thickening. The solution isfcooled down.Then 30 parts of a solution of sodium nitrite" (30%) are added whilststirring. Apreparation, containing the ester salt precipitates in a finedispersiomis obtained,

When cotton is printed with this preparation and the print developed, asindicated in Example 1, there is obtained an even, deep brown print.

Example The following printing preparation is made ups 40 parts of thesodium salt of'the acid sulfuric acid ester of leuco-2:l-naphthioindigo,corresponding to 50% of Val: dyestuff are dissolved in the heat with 320parts of water, 50 parts of lactate of the trihydroxyethylether oftriethanolamine and 500 parts of a neutral starchjtragacanth thickening.The solution is cooleddown whilst stirring; Tofthe coldisolution thereare added, whilst stirring, 30 partsoi a solution'of ammoniumthiocyanate (50% 4'0parts ofja solution of sodium chlorate (25%3,;iparts oi a solution of ammonium vanadate (1% and 10 parts of ammonia(25%). 1 j.

-When' cotton is printed WithYthis preparation and the print developed;as indicated'in Example 2, there is obtained an' even, deep'brown'print,

r In the above ekample the '50 parts"of "the""lacf tate of thetrihydroxyethyletherpf the-trietha nolamine may be replaced withsubstantially,

equivalent results by 80 parts of the moaocme m:

acetate of v the triethanolamin'e and of water by 290 parts of Water.

, immptlefi,

the 320 parts Thefollowing printingipreparatm .igj mgd apt: 40 parts ofthe d imssaltor the acid sulfuric acid ester of leuco- -2':1-'6i'SanthraquinOne-diphenylthiazol, corresponding .to-5o%% of L vat:dy'estuil- "are dissolved by; heatin'grwith 260 :parts 0f Water, 1001parts of the lactate ofwthe 'tri-hydroxyolyethylether1of;-thel1triethanolamine 1-:(.obtained I by-the reactionof 18moleculesjethylenetoxide on" triethanolamine in; aqueous, solution) ,2and 500: parts of :a neutral starch tragac'anth', thickening. 5: is;cooled' down; wgflhen there xare 1 V Qirlasolutionxof; arts o :.;a":

he-13 mm d d whi st-sti rin .10am mmo m thio ap 4 0 p her yle at; of thetnhydroi zypolv eth ther of trietha oxide in methanol solution).

, 10 The following printing preparation is made up;

nolamine may be replacedwithfsubstantially equivalent results by 50partsof the monochloroacetate offth'is' ether andthe'gfiilparts of water vExample 7; a H The following printing preparation ismade up': 40 partsof the sodium saltof-the'acid sulfuric acid ester of the leuco-2:1-6:5-anthraquinone diphenylthiazole, corresponding to% of vatdyestufl', aredissolved by heatingwith 340 parts of water, parts of theoxalate of the trihydroxy-polyethylether of triethanolamine (see Example 6) and-500 parts of a neutral starch tragacanth thickening. Thesolution is cooled down.

To the cold solution there are added, whilst stirring, 40 parts of asolution of 'sodiumnitrite (30%) and 20 parts of a solution of sodiumcarbonate (10%).

When cotton is printed with this preparation and the print developed,as-indi'cated in Example 1, there is obtained an even vivid anddeepcanary yellow print.

In the above example the 60 parts of the oxalate of thetrihydroXy-polyethylether may be replaced with substantiallyequivalentresults by 40 parts of the tartrate ofthis ether "and the 340parts of water by 360'parts of water.-

. I Eil:dmple8 The following printing paste is madeup: I 40 parts of thesodium salt of the acid'sulfuric' acid ester of the -leuco-2:1'-6:5-'anthraquinone-diphenylthiazol,"corresponding to 50% of vatdyestuif, arerdissolved by heating fwith 350 parts of *water, 50 partsof the phthalate of triethanolamine and 500v parts of a neutral starchtragacanth thickening; The solution is cooled' 'down and thenzthere'areadded, whilst stirring, 40 parts of. 'a sodium nitrite solution (30%")and ZOpart-s of a sodium" carbonate solution (10%).

r When cotton is printed: with'this 1 preparation and the printdeveloped; as I indicated in Exam ple, 1,; there isobtained an even'canary-yellow prints 'Example' f low g m n m' ar' tiefi-i m d um "40 a sme sa im' sait' r th cidumac I t "-anth'anthrone, corresponding toj 50%fo'i vat dyestuif; are dis-c p i e ing w hfllqijp rt b wat r; 10 parts ofthe 'tartrateof the trihydro y polyethyl-C' etherof' triethanolamine(seeE 'raniple: 6), and? j 500 parts of a neutral starch tra'gacanththickeri -i mg: 'The solu'tion is cooled downand'thentherej,

are adiiedywhilst stirririgw 30 p rts era isog um 1, there is obtaineda: deep, viviu'orangepnat;

'agid nitrite solution t30% rid-20 parts "of"a-sodiur'n'-carbonate'solutioii"(10%)? When cotton is printed with th pre a'r'ationandtthe print' developed, "as fir'idicate'ci in Exam le E m Thefollowing printing preparation is madelupr-J e il-partsotthegsodiumqsalt: ofcthe-acid sulfuric ter of, --;th e leuco1-2 1 6:5.-ganthraquinone-;

, cha ts-entire ,dimethylan'ilineipara 'i pf the;.trihydroxyethylethenpf "trietha-t v-spaia of a sodium; nitritesolution(30),;%and. 20 '1" parts of a sodium carbonate solution (10%).

arts of;a. neutralistarch traga l aa'raavo When cotton is printed withthis preparation and the print developed, as indicated in Example 1,there is obtained a deep canary-yellow print.

' Example 11 The following printing preparation is made up:

40 parts of the sodium salt of the acid sulfuric acid ester of theleuco-2:1-6:5-anthraquinonediphenylthiazol, corresponding to 50% of vatdyestufl, are dissolved by heating with 240 parts of water, 120 parts ofthe naphthalene-l-sulfomate of the trihydroxyethylether oftriethanolamine and 500 parts of a neutral starch tragacanth thickening.The solution is cooled down and then there are added, whilst stirring,40 parts of an ammonium thiocyanate solution (50%), 50

parts of a sodium chlorate solution (25%) and The following printingpreparation is made up:

40 parts of the sodium salt of the acid sulfuric acid ester of theleuco-2:'1-6:5-anthraquinone-diphenylthiazol, corresponding to-50% ofvat dyestuff, are dissolved by heating with 300 parts of water, 100parts of the sulforicinoleate of the trihydroxyethylether oftriethanolamine and 500 parts of a neutral starch trag'acanththickening. The solution is cooled down and then there are .added,whilst stirring, 40 parts of a sodium nitrite solution (30%) and partsof a sodium carbonate solution (10%).

When cotton is printed with this preparation and the print developed, asindicated in Example 1, there is obtained a deep canary-yellow print. I

In the above example the 100 parts of the sulfo- ,ricinoleate may bereplaced by 100 parts of the oleate of the trihydroxyethylether oftriethanolamine.

Example 13 The following printing preparation is made up:'

60 parts of the sodium salt of the acid sulfuric acid ester of theleuco-6:6-diethoxy-thioindigo, corresponding'to of vat dyestuiif aredissolved by heating with 338 parts of water, 20 parts of the phthalateof the trihydroxy-polyethylether of triethanolamine (see Example 6) and500 parts of a neutral starch tragacanth thickening. The solution iscooled down and then there are added parts of an ammonium-thiocyanatesolution 32 parts of a sodium* and the print developed as indicated inExample 2. there is obtained an even, vivid and .deep orange print.

Example 14 The following printing preparation is made up: 40 parts ofthe sodium salt of the acid sulfuric acid ester of theleuco-6:6'-dichloro-4:4'-dimethylthioindigo, corresponding to 50% of vatdyestuff, are dissolved by heating with 310 parts of water, 50 parts ofthe lactate of the trihydi'oxyethylether of triethanolamine and 500parts of a neutral starch traga-canth thickening. The soluion is cooleddown and then there are added, whilst stirring, 80 parts of a sodiumnitrite solution (30%) and 20 parts of a sodium carbonate solution (10%)The preparation thus obtained contains the ester salt precipitated infinely divided form.

When cotton is printed with this preparation and the print developed,-asindicated in Example 1, there is obtained avivid, deep rose-coloredprint,

Example 15 The following printing preparation is made up: 60 parts ofthe sodium salt of the acid sulfuric acid ester of theleuco-dibromo-3:4-8:9-dibenzpyrenquinone, corresponding to 30% of vatdyestuif, are dissolved by heating with 350 parts of water, 40- parts ofthe lactate of the trihydroxyethylether of triethanolamine and 500 partsof a neutral starch tragacanth thickening. The solution is cooled downand then there are added, whilst stirring, 30 parts. of a sodium nitritesolution (30%) and 20 parts of a sodium carbonate solution (10%). Thepreparation thus obtained contains the ester salt precipitated in finelydivided form.

When cotton is printed with this preparation and the print developed, asindicated in Example 1, there is obtained a vivid deep and evengoldenyellow print.

' Example 16 The following printing preparation is made up: 40 parts ofthe sodium salt of the acid sulfuric acid ester of leuco-dibromoanthanthrone, corresponding to 50% of vat dyestuflf, are dissolved byheating with 360 parts of water, parts of the lactate of a mixturecontaining hydroxyethers of r When cotton is printed with thispreparation and the print steamed for 4 minutes in a Mather- Plattapparatus and afterwards* developed by treating for 2 seconds at 35 C.in a bath containing 40 com. of cone. sulfuric acid and 30 gr. of sodiumbichromate per liter and by a subsequent air passage of 2 0 secondsthere is obtained, after the usual washing and soaping at the boil, an.even deep orange print.

What I claim is:

1. A printing composition, comprising an ester salt of a leuco vatdyestuff, the lactate of trihydroxyethylether of triethanolamine and athickening agent.

2. A printing composition comprising the sodium salt of the sulfuricacid ester of leuco dibromoanthanthrone, the lactate of the trihydroxyethylether of triethanolamine and a thickening agent.

. 3. ,A printing composition cultly soluble ester salt of a leuco vatdyestufi; a salt of a. primary to tertiary nitrogenous organic base,which contains at least one ether-linkedoxygen atom and, as solubilizinggroup, at least one hydroxyalky'l group, with an unesten'fied organlcacid selected from the group consisting of the carboxylic acidscontaining not more than five carbon atoms in an open chain and thearomatic aminosulfonic acids; and a thickeningagent.

4. A printing composition comprising-a, diflicultly solubl ester salt ofa leuco vat dyestu'fl'; a,

comprising a difiisalt of a primary to tertiary nitrogenous organicbase, which contains at least one ether-linked oxygen atomand, assolubilizing group, at least one hydroxyalkyl group, with anunesterifled alig'ahaticcarboxylic acid containing not more than-fivecarbon atoms in an open chain; andv a thickening agent.

5. A printing composition comprising a diificultly soluble ester salt ofa leuco vat dyestuff; a salt of ja primary to tertiary nitrogenousorganic base, which contains at least one ether-linked oxygen atom and,as solubilizing group, at least one hydroxyalkyl group, with anunesterified aromatic carboxylic acid; and a thickening agent.

6. A printing composition comprising a diflicultlysoluble ester salt ofa leuco vat dyestufi a salt of a primary to tertiary nitrogenous organicbase, which contains atleast one ether-linked oxygen atom and, assolubilizing group, at least one hydroxyaikyl group, with anunesterified aromatic aminosuifonic acid; and a thickening agent.

7.A printing composition comprising a dimcultiy soluble ester salt of aleuco vat dyestufi; a salt of a primary to tertiary nitrogenous organicbase, which contains at least one ether-linked oxygen atom and, assolubilizing group, at least one-hydroxyalkyl group, withdimethylaniline-psulionic acid; and a thickening agent.

8. A printing composition comprising a difiicultly soluble ester salt ofa leuco vat dyestufi; a

salt of a primary to tertiary nitrogenous organicbase, which contains atleast one ether-linked oxygen atom and, as solubilizing group, at leastone hydroxyalkyl group, with lactic acid; and a thickening agent.

9. A printing composition comprising a diflicultly soluble ester salt ofa leuco vat dyestuff; a salt of a primary to tertiary nitrogenousorganic base, which contains at least one ether-linked oxygen atom and,as solubilizing group, at least, one hydroxyalkyi group, withphthalicacid; and a thickening agent.

10. A printing composition comprising a difiicultly soluble ester saltof a leuco vat dyestuff, the dimethylaniline-p-sulfonate of thetrihydroxyether of triethanolamine, and a thickening agent.

11. A printing composition comprising a difficultly soluble ester saltof a leuco vat dyestufi, the phthalate of the trihydroxyether oftriethanolamine, and a thickening agent.

JACQUES DUPORT.

